The best place I know to start looking for patterns is www.ravelry.com. It's free to join. Knowing your approximate gauge with your yarn would be helpful. You can search for vest patterns and specify a yarn weight, look at the gauge needed for various weights of yarn, and determine which one yours matches. Here's a search for men's vests there. http://www.ravelry.com/patterns/sear...t=adult%2Bmale

__________________~ GG

Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper

To the OP: Without knowing where you live (at least which country), it's difficult to give good advice.

The way knitting needles are sized varies. There are three systems currently in use: the metric system, the United States system, and the UK system. Simply saying "I'm looking for a yarn with __ stitches to the inch/cm on __ needles" may not be sufficiently specific unless you use the metric measurement for needles. Size 4 needles, for example, are fairly small in the American system, and fairly large in the British system, but 4.0mm needles are a nice medium (US #6).

As you've seen, systems for referring to the size of yarn also vary. This page, courtesy of the Craft Yarn Council of America, gives some guidance as to stitches per inch/cm of fine to extra-chunky yarns on various sizes of needles (or crochet hooks) for metric and American needles/hooks, but it ignores the existence of the British numbering system.

However, in combination with the Ravelry chart I linked to previously, the CYCA standards should help you rephrase your "quest."